One approach to breast reconstruction is the harvesting of autologous tissue from other sites on the patient's own body for use in place of removed breast tissue. This can include but is not limited to the following tissue extractions known in the art: latissimus dorsi flap, transverse rectus abdominus myocutaneous (TRAM) flap, deep inferior epigastric artery perforator (DIEP) flap, latissimus dorsi myocutaneous (LDM) flap, and superior gluteal artery perforator (SGAP) flap. There are significant drawbacks to the use of autologous tissue grafts, in particular the requirement for healing at the secondary location from which tissue is taken.
Approximately 70-80% of all breast reconstructions performed in the United States utilize a technique referred to as a “skin sparing mastectomy” where the initial cancer surgery and breast reconstruction are performed in a single procedure. Specially treated cadaveric, bovine, and porcine tissues including acellular dermis, acellular pericardium, and/or acellular porcine dermis are used to create a tissue sling between the inferior border of the pectoralis muscle and the inframammary fold. The combination of tissue sling and pectoralis muscle provides a pocket in which a tissue expander is placed to facilitate expansion of the pocket for future placement of a permanent breast implant 3-6 months in the future after healing has occurred.
Although this is the dominant reconstruction technique for breast cancer, it has several well documented complications. The most documented is seroma formation. Seroma is a fluid accumulation within the surgical site that if left unattended can lead to infections and possible loss of the implanted tissue expander. There is a wide range in severity of seromas, with some easily treated by the surgeon through needle aspiration and others requiring surgical debridement and closure.
It is the current opinion of most plastic surgeons that the very smooth acellular tissues of the tissue sling allow the subcutaneous tissues to slide or easily move during the early part of the patient's recovery. As with skin grafts, tissue movement slows the healing process. With this type of breast reconstruction procedure, tissue flap movement above the tissue sling not only retards healing but can exacerbate fluid accumulation and seroma formation.
U.S. Patent App. Pub. No. 2014/0081397 discloses breast reconstruction procedures aimed at selecting a breast implant size that avoids excessive tension in surrounding tissue and proper breast implant position and symmetry. An acellular dermal matrix is sutured to the chest wall under the pectoralis muscle to provide a hammock for a breast implant. While the procedures offer insights into optimization of implant sizing, no attention is given to manner in which the incisions are closed let alone stabilization of the skin flap. Thus, the disclosed procedures are susceptible to the same post-operative complications (e.g., seroma formation) of other skin sparing mastectomy techniques.
U.S. Patent App. Pub. No. 2014/0276993 discloses an absorbable synthetic braided matrix for breast reconstruction and hernia repair. For breast reconstruction, the matrix may serve as an internal hammock or sling to support a tissue expander, breast implant, or breast tissue. In essence, the matrix may be used instead of biological slings prepared from, for example, porcine or bovine tissue. A drawback to this device is insufficient stabilization of the tissue flap relative to the matrix. Problems such as seroma formation may arise similar to the case of using acellular tissue slings. Another disadvantage of this device is that it is designed to degrade after a period of six to twelve months after implantation. After such time, support of a tissue expander or breast implant must be supplied by the patient's cellular ingrowth into the matrix. As such, the implant itself provides no guarantee of long term support.
U.S. Patent App. Pub. No. 2007/0021779 discloses surgical fasteners having two halves which pull together in a manner akin to a cable tie. Each half is imbedded in the opposite side of a wound or laceration. As the two halves are pulled together, the opposing sides of the wound are likewise pulled together, closing the opening. A limitation of the surgical fasteners is their application to tissue approximation of a single tissue layer. They fail to provide stabilization between adjacent layers and permit sliding between the layer in which the fastener is imbedded and adjacent tissue layers or structures.
U.S. Patent App. Pub. Nos. 2007/0156175 and 2008/0208251 disclose devices for attaching, relocating, and reinforcing tissue. In an embodiment, two support plates with angled barbs are connected to one another via suture or a mesh material. As in 2007/0021779, discussed above, the two ends may be brought together to adjust the distances therebetween. Again, the application is directed to tissue approximation, and no configuration is disclosed which provides flap stabilization in a reconstructed breast.
In the field of breast reconstruction surgery, problems such as seroma formation persist in spite of developments in the fields of wound healing and tissue approximation such as the devices and methods disclosed in the patents and published patent applications discussed above.